Turbo coupe intercooler: Big stupid hood scoop?

[drdanteiii]

I scored a free turbo coupe intercooler for our 24hours of lemons XR. I did some searching on the forum here but didnt really get the answer I was looking for. So my question is:

If I'm running a TC intercooler, will a big stupid looking hood scoop flow enough air to make a difference, or would I be better served by running underhood ducting to get air there. Blower fan is a no-go due to budget constraints.

I care not one bit about how bad its going to look. Heat soak at a dead stop is not a big issue, if the car is running, it will be moving on the track.

something like this seems appropriate to my sheet metal fab skills.



The goal is not more power, but more reliability. Our current set up: we are now running an auxilliary oil cooler and a saab radiator, and our factory boost controller is bypassed, limiting us to about 10psi. Just want to add the intercooler as an added level of security.

[drdanteiii]

gratuitous pic of our car in action:



and yes, i will be sad to cut into our awesome graphics.

[John Brennan]

I believe it's better to duct air from the front end, as most of the overhood air is low-pressure. The Cossies put the vents up towards the front of the hood for that reason. You can also duct air from the base of the windshield area, but then you're counteracting your pressure differential through the radiator. You can also supplementally force-feed your ducted air with a squirrel-cage or motorcycle fan.

[DPDISXR4Ti]

Can you find a way to put one of those PVC pipes to good functional use by turning it into an air scoop? Just have it make a 90-degree turn through the roof, then a 45 through the center of the cabin and through the firewall, and then plumb over to the top of the IC. If you mount the IC in the (factory) battery location, you'll just be adding to the cowl-inducted down-draft in that area.

[John Brennan]

Can you find a way to put one of those PVC pipes to good functional use by turning it into an air scoop? Just have it make a 90-degree turn through the roof, then a 45 through the center of the cabin and through the firewall, and then plumb over to the top of the IC. If you mount the IC in the (factory) battery location, you'll just be adding to the cowl-inducted down-draft in that area.

In order to access that (cowl-inducted downdraft), you have to cut a hole in or otherwise modify the false firewall.

[Ed Lijewski]

Use that passenger headlight opening to duct air to the TCIC.

YMMV

[John Brennan]

Use that passenger headlight opening to duct air to the TCIC.

YMMV

An excellent suggestion.

[wicked93gs]

A hood scoop will indeed be the best way to do it(which is after all the reason the SVO had one). However...keep in mind that for proper ducting you will need a rubber seal that seals to the top flange of the IC. I very much doubt you will be able to effectively duct the air from the front of the car, I doubt there is enough room between the IC and the hood to make an effective hat for the intercooler. It will be far easier with a hood scoop...

[C-Rock]

No one ever takes into consideration the over all shape of the car when doing this. I forget what the co-effient drag of the car is but I remember it being a very low number. Just because you add a big air scoop to the car does not mean air is going to go through it. If air does not flow out the bottom real well it's not going to even go in the air scoop and you could add this scoop and the air is then routed around it because of the shape of the car. Yes the SVO had a scoop but it was designed in a wind tunnel and Ford made sure air went in and out of the IC. Your cutting yourself so short in IC by adding the Turbo Coupe IC and mounting it in the worst over all place above the Turbo. Ford did this for a few reason's one being they needed to keep the AC and it was just cheaper to add the IC in this spot vs re-designing the whole front end of the Turbo Coupe and the SVO. Just because you add the IC it does nothing for reliability the IC is all about more power and 10 psi isn't even stock PSI. Unless you have access to a wind tunnel and can then stick the IC and scoop on the car and see if air flows through it I would go with the standard and mount a front of the Rad type IC. Also adding a fan to duct the air is cutting your self short as well, if the fan can only run say 100 CFM and you can run say 1000 CFM going 50 miles an hour your sure going to cool the intake air so much better with 1000 CFM then a small 100 CFM fan.

[C-Rock]

Also the RS 500 vents have a front lip on them and this causes a vortex and this suck's air up and out of the engine bay. Under the hood with the turbo is a very hot place and moving air through the rad and out of the engine bay kept the engine running cooler. If you get a chance to look at the Ford GT 40 it has a big inverted hood scoop right behind the rad so air went in through the rad and out to keep the engine cool. This back when Ford was giving Ferrari a beating.

[John Brennan]

A hood scoop will indeed be the best way to do it(which is after all the reason the SVO had one). However...keep in mind that for proper ducting you will need a rubber seal that seals to the top flange of the IC. I very much doubt you will be able to effectively duct the air from the front of the car, I doubt there is enough room between the IC and the hood to make an effective hat for the intercooler. It will be far easier with a hood scoop...

In fact there's more than enough room, especially if you use the late (dipped center) valve cover and the shorter TC upper intake. Mock it up and take some measurements-- you'll see, and the air in front of the car has much higher pressure than the air on top of the hood. Why cut up your hood? There is no need. It wasn't just the little spoilers on the fronts of the vents that drew air up through them; the front of the hood is already a low-pressure area because of the angle between it and the grille. Air hits the grille and cannot maintain laminar flow at the front of the hood, creating a low-pressure bubble, plus the air coming in through the grille causes a higher pressure under the hood than over it. The other function of the Coosie hood vents is to negate front end lift caused by this. The over-the-hood air pressure increases as you move back, becoming neutral in the middle (about where you'd have your hood scoop), and then becoming high-pressure as it piles up at the base of the windshield. The false firewall seals this air into the HVAC system, both providing an underway pressure feed for the cabin vents, and also preventing engine fumes from reaching the inside. A cowl vent will draw substantial air over an IC core if you broach this, but now you are negating the pressure differential between the front of the car and the engine room, reducing your flow through the radiator.

None of thhis is a huge deal or anything, but that's how the air flows at the front of the car. I can only believe that running a simple bit of ducting from the headlight openings as Ed suggested, connected to something fabbed from sheet aluminum over the core, wouldn't be far easier and more effective than cutting a hood scoop.

[Ed Lijewski]

A hood scoop will indeed be the best way to do it(which is after all the reason the SVO had one). However...keep in mind that for proper ducting you will need a rubber seal that seals to the top flange of the IC. I very much doubt you will be able to effectively duct the air from the front of the car, I doubt there is enough room between the IC and the hood to make an effective hat for the intercooler. It will be far easier with a hood scoop...

Check out Mazdaspeeds' ducting from below the hood and above the "grill" to the compressor intake near the firewall.

YMMV

[John Brennan]

That, plus not having the headlights installed and having that available for this use is about as expedient and obvious as dropping a piece of steak in front of a German Shepherd.

"Woops, I'll have to clean that up-- oh, wait-- never mind."

[ninja z28]

I had an extra hood and cut the metal pushed it up and made a scoop. The intercooler would still get hot. I would just do a front mount. I will see if i can find a pic.

[C-Rock]

Exactly on the getting hot. If anyone has seen the glowing red hot turbo they would kind of go " "Huh" I'll bet that IC never gets cold I don't think there is any amount of air you can run past that turbo coupe IC and have it ever get cold with a turbo as hot as the sun sitting under it.